Historical tsunamis · May 7, 1986, 10:47 PM UTC
1986 Andreanof Islands, Ak tsunami
United States
The tsunami of May 7, 1986, 10:47 PM UTC originated near Andreanof Islands, Ak (United States).
Key facts
- Date
- May 7, 1986, 10:47 PM UTC
- Cause
- Earthquake
- Magnitude
- M8.0
- Depth
- 31 km
- Maximum documented water height
- 0.90 m
- Damage
- moderate (about US$ 1–5 million)
- Observation records
- 66
- Countries affected
- 14
It was triggered by a magnitude 8.0 earthquake at a depth of 31 km.
The highest documented water height was 0.90 m.
66 observation sites in 14 countries are recorded.
Outside the source country, the earliest documented arrival was at Nikolskoe, Bering I, Commander I (Russia) after 3:13 h.
Damage is estimated at moderate (about US$ 1–5 million).
Map of observation sites
66Each dot is a documented observation site; colour and size show the observed water height. The triangle marks the source.
Tsunami arrival times
Documented arrival times from the NOAA/NCEI database, showing the earliest recorded location per country. Coverage is incomplete: a country without an entry was not necessarily spared.
- 0:00 hEarthquake (origin) · May 7, 1986, 10:47 PM UTC
- 0:18 hUnited States · Adak, Sweeper Cove, Ak · 0.88 m
- 3:13 hRussia · Nikolskoe, Bering I, Commander I · 0.09 m
- 3:23 hUSA Territory · Midway Islands · 0.34 m
- 3:23 hJapan · Ofunato · 0.07 m
12 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| United States | 17 | 0.88 m Adak, Sweeper Cove, Ak | — | 0:18 h |
 Canada | 1 | 0.70 m Cape Scott, Vancouver Island | — | — |
| USA Territory | 4 | 0.34 m Midway Islands | — | 3:23 h |
 Chile | 3 | 0.22 m Coquimbo | — | — |
 New Zealand | 1 | 0.20 m Lyttelton | — | — |
 Japan | 29 | 0.15 m Ayukawa | — | 3:23 h |
 Russia | 2 | 0.09 m Nikolskoe, Bering I, Commander I | — | 3:13 h |
 Peru | 2 | 0.07 m Callao la Punta | — | — |
 Ecuador | 2 | 0.07 m La Libertad | — | — |
 French Polynesia | 1 | 0.07 m Papeete, Tahiti | — | — |
 Samoa | 1 | 0.03 m Apia, Upolu Island | — | — |
| Micronesia, Fed. States Of | 1 | 0.03 m Truk Islands, Caroline Islands | — | — |
 Cook Islands | 1 | 0.01 m Rarotonga | — | — |
 Australia | 1 | — | — | — |
Highest documented water heights
15 / 66Individual documented observations for this event. Heights come from different measurement types and sources; not every location has a measured height.
| Location / station | Observed height | Distance from source | Country |
|---|---|---|---|
| Adak, Sweeper Cove, Ak · Ak | 0.88 m | 134 km | United States |
| Cape Scott, Vancouver Island · Bc | 0.70 m | 3,189 km | Canada |
| Kapaa, Kauai, Hi · Hi | 0.60 m | 3,530 km | United States |
| Hanalei, Kauai, Hi · Hi | 0.50 m | 3,510 km | United States |
| Nawiliwili, Kauai, Hi · Hi | 0.39 m | 3,542 km | United States |
| Midway Islands · Hi | 0.34 m | 2,597 km | USA Territory |
| Hilo, Hawaii, Hi · Hi | 0.28 m | 3,926 km | United States |
| Coquimbo · Coquimbo | 0.22 m | 13,451 km | Chile |
| Honolulu, Oahu, Hi · Hi | 0.20 m | 3,660 km | United States |
| Lyttelton · Canterbury | 0.20 m | 10,609 km | New Zealand |
| Kahului, Maui, Hi · Hi | 0.18 m | 3,752 km | United States |
| Ayukawa · Miyagi | 0.15 m | 3,685 km | Japan |
| Mera · Chiba | 0.15 m | 4,040 km | Japan |
| Chichijima Island · Bonin Is, Tokyo | 0.14 m | 4,497 km | Japan |
| Kushimoto · Wakayama | 0.14 m | 4,425 km | Japan |
More tsunamis
Source: NOAA National Centers for Environmental Information (NCEI), Global Historical Tsunami Database. Confirmed events only. Deaths and damage are database estimates; older records are incomplete. Water heights come from different types of observation.